1 files changed, 47 insertions, 0 deletions
diff --git a/system/libraries/format/bytes.zig b/system/libraries/format/bytes.zig
new file mode 100644
index 0000000..9d4cb86
--- /dev/null
+++ b/system/libraries/format/bytes.zig
@@ -0,0 +1,47 @@
+//! Byte size formatting
+
+const int = @import("int.zig");
+
+pub fn format(bytes: u64, buf: []u8) []const u8 {
+    const kb = bytes / 1024;
+    const mb = kb / 1024;
+
+    if (mb >= 1024) {
+        // Round: add 512 (half of 1024) before dividing
+        const gb_tenths = (mb * 10 + 512) / 1024;
+        const gb_whole = gb_tenths / 10;
+        const gb_frac = gb_tenths % 10;
+
+        var pos: usize = 0;
+        const whole_str = int.toStr(gb_whole, buf[pos..]);
+        pos += whole_str.len;
+        buf[pos] = '.';
+        pos += 1;
+        buf[pos] = '0' + @as(u8, @intCast(gb_frac));
+        pos += 1;
+        buf[pos] = ' ';
+        pos += 1;
+        buf[pos] = 'G';
+        pos += 1;
+        buf[pos] = 'B';
+        pos += 1;
+        return buf[0..pos];
+    } else if (mb > 0) {
+        const num_str = int.toStr(mb, buf);
+        buf[num_str.len] = ' ';
+        buf[num_str.len + 1] = 'M';
+        buf[num_str.len + 2] = 'B';
+        return buf[0 .. num_str.len + 3];
+    } else if (kb > 0) {
+        const num_str = int.toStr(kb, buf);
+        buf[num_str.len] = ' ';
+        buf[num_str.len + 1] = 'K';
+        buf[num_str.len + 2] = 'B';
+        return buf[0 .. num_str.len + 3];
+    } else {
+        const num_str = int.toStr(bytes, buf);
+        buf[num_str.len] = ' ';
+        buf[num_str.len + 1] = 'B';
+        return buf[0 .. num_str.len + 2];
+    }
+}